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Tao Hu

Bio: Tao Hu is an academic researcher from Hubei University of Technology. The author has contributed to research in topics: Materials science & Compatibilization. The author has an hindex of 4, co-authored 21 publications receiving 72 citations.

Papers
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Journal ArticleDOI
TL;DR: In this article, strong and tough polyvinyl alcohol (PVA)/alginate hydrogen-bonded-ionic dual-physical double-network (DN) hydrogels have been successfully prepared by a facile route of a freeze-thaw (25 − 25 − 25 °C) cycle.
Abstract: Strong and tough poly(vinyl alcohol) (PVA)/alginate hydrogen-bonded-ionic dual-physical double-network (DN) hydrogels have been successfully prepared by a facile route of a freeze–thaw (25–25–25 °C) cycle followed by concentrated (1.0 mol L−1 of) aqueous-Ca2+ immersion of PVA/Na alginate (SA) mixed aqueous solutions. It was found that, at mole ratios of the PVA- to SA repeat units of 20/1 to 80/1, the DN gels likely evolved a semi-interpenetrating polymer network (IPN) morphology of rigid alginate networks dispersed in while interlocking with ductile PVA network to accomplish DN synergy that gave their high strength and toughness, where the high alginate rigidity originated probably from its dense cross-link induced syneresis and dispersion along crosslink-defective voids to result in little internal stress concentration. Tentatively mechanistically, as the 20/1–80/1 DN gels were stretched steadily, their mechanical response was gradually differentiated into distinct synergistic states: the sparsely hydrogen-bonded PVA served as a ductile matrix to bear small fractions of the established stresses at its large elongations; whereas the densely ionically (i.e. Ca2+) cross-linked alginate functioned as a rigid skeleton to sustain the remaining larger stresses upon its smaller local strains. Promisingly, this ductile-rigid matrix-skeleton synergistic mechanism of semi-IPN morphology may be universally extended to all A/B DN hydrogels of large A–B rigidity (or cross-link density) contrast, whether the cross-link nature of network(s) A or B is covalent, ionic, hydrogen bonded or van der Waals interacted. The strong and tough DN gels also displayed satisfactory self-recovery of viscoelastic behaviour, in that their Young's modulus and dissipated energy in the uniaxial tensile mode and dynamic storage and loss moduli in the oscillatory shear mode all recovered significantly from non-linear viscoelastic regimes despite different degrees of failure to revert to (quasi)linear viscoelasticity.

36 citations

Journal ArticleDOI
TL;DR: In this article, 3,3,3-Trifluoropropylmethyldimethoxysilane (TMDMS) was successfully grafted to molecules of epoxy resin (EPR) of bisphenol-A origin with an epoxy value of 0.440, by transesterification (i.e. alcoholysis) of the TMDMS methoxyls with the EP44 hydroxyls under anhydrous dibutyltin-dilaurate catalysis.
Abstract: 3,3,3-Trifluoropropylmethyldimethoxysilane (TMDMS) was successfully grafted to molecules of an epoxy resin (EPR) of bisphenol-A origin with an epoxy value of 0.440, i.e. EP44, by transesterification (i.e. alcoholysis) of the TMDMS methoxyls with the EP44 hydroxyls under anhydrous dibutyltin-dilaurate catalysis. Meanwhile, a nanosilica powder was modified with 1,1,1,3,3,3-hexamethyldisilazane (HMDS) via electrophilic substitution of the nanosilica hydroxyls by the HMDS trimethylsilyls to significantly decrease its surface hydroxyls for controlled aggregation. Six coatings, onto an NaOH solution-treated tinplate substrate, of EP44, of the TMDMS-grafted EP44, and of the composites of the TMDMS-grafted EP44 filled with 0.5, 1, 3 and 5 wt% of the HMDS-modified nanosilica were then step-cured mildly with an amino-terminated polyamide from a solution. Owing to the introduction of superhydrophobic trifluoropropyls possibly plus a reduction in the hydrophilic hydroxyl concentration present, the hydrophobicity, evaluated by the water contact-angle, of the EP44 coating increased considerably upon its TMDMS grafting, which then changed little with further addition of the nanosilica. Electrochemical impedance spectroscopy data and simulations revealed that the anticorrosive performance of the TMDMS-grafted EP44 coating, upon immersion into an NaCl solution, was significantly improved compared with the EP44 coating, primarily due to its remarkably enhanced hydrophobic barrier to the water-mediated corrosives (water, NaCl, oxygen, other molecules and ions, etc.). However, the anticorrosion behaviour of the composite coatings was dominated by a corrosion inhibition (i.e. physical barrier) mechanism by the nanosilica filling the pores (free volumes, voids, cracks, etc.) susceptible to the corrosives. As the nanosilica content steadily was raised from 0 to 5 wt%, the corrosion inhibition of the composite coatings first intensified, probably thanks to an enhancement of the filling rate of the pores, and subsequently weakened, presumably due to an increase in the porosity from increased size exclusion of aggregated nanoparticles, and finally improved again possibly owing to a densification of the outside-of-pore barriers of greatly aggregated, size excluded particles, which constituted dual critical concentrations (DCCs) of the nanosilica at 0–0.5 and ∼3 wt%, respectively, that gave rise to a maximum followed by a minimum in the corrosion inhibition. To our knowledge, this has been the first work reporting this unique DCCs behaviour for EPR/nanosilica coatings, which, dictated by a hydrophobic EPR matrix of small porosity as well as a modified nanosilica of controlled aggregation, may universally be extended to the corrosion inhibition of other polymer/nanoceramic coatings.

24 citations

Journal ArticleDOI
10 Jan 2020
TL;DR: In this article, the superhydrophobic surfaces of silicone rubber with different microstructure were directly prepared by texturing with a nanosecond fiber laser, which results in a smaller contact area with the water droplet due to greater roughness and root mean square slope.
Abstract: In this paper, the superhydrophobic surfaces of silicone rubber with different microstructure were directly prepared by texturing with a nanosecond fibre laser. The superhydrophobic surfaces have excellent anti-icing performance. Even at 0 ° C, the superhydrophobic surface has a contact angle of ~150° and a rolling-off angle of ~2.5°. The superhydrophobic silicone rubber surfaces with different microstructures have obvious differences in contact behaviours with water droplets at low temperatures. The surface textured with a laser fluence of 10 J cm has a larger particle size and more abundant micro-nano particles, which results in a smaller contact area with the water droplet due to greater roughness and root mean square slope. The deeper the small gaps on the superhydrophobic surface, the more time it takes for the change in contact state between the surface and the water droplets. The adhesion strength of the superhydrophobic rubber surfaces with the ice layer were smaller due to the air stored between the surfaces and the ice layer. In particular, the laser textured surface with an laser fluence of 10 J cm has the lowest ice adhesion strength due to its layered micro-nano composite structure. After 30 cycles of icing and de-icing, the processed silicone rubber surface still retains excellent hydrophobicity. The superhydrophobic silicone rubber surface has important value in anti-icing and anti-pollution applications.

15 citations


Cited by
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Journal ArticleDOI
TL;DR: In this paper, the polydopamine modified barium titanate (BaTiO3, BT) nanoparticles have been anchored onto the surface of electrospun poly (vinylidene fluoride-trifluoroethylene) P(VDF-TrFE) fibers to fabricate hierarchical micro-structured membrane, which not only effectively avoids the agglomeration of nanofillers but also enhances the density of interfaces in the nanocomposites.

187 citations

Journal ArticleDOI
TL;DR: A comprehensive and critical assessment of laser-textured superhydrophobic surfaces on various substrate materials was done in this article, where laser texturing, involving the creation of patterns on material surfaces, is considered an efficient and facile approach to fabricate hierarchical surface structures on various material types.

65 citations

Journal ArticleDOI
TL;DR: Insight is provided into the influence of hydrogel property on H-TENG performance and guidance is given for designing and fabrication of highly stretchable and transparent TENGs.
Abstract: Triboelectric nanogenerators (TENGs) with high transparency and stretchability are desired for invisible and adaptable energy harvesting and sensing. Hydrogel-based TENGs (H-TENG) have shown promis...

60 citations

Journal ArticleDOI
01 Apr 2021
TL;DR: This review focuses on recent advances in synthesis and applications ofpolysaccharide‐based hydrogels by capitalizing on a set of biocompatible and biodegradable polysaccharides (i.e., cellulose, alginate, chitosan, and cyclodextrins [CDs]).

58 citations